System for maintaining the oil level in the crankcase of internal-combustion engines



R. K. HUNGERFORD SYSTEM FOR MAINTAINING THE OIL LEVEL IN THE CRANKCASE OF INTERNAL-COMBUSTION ENGINES 2 Sheets-Sheet 1 0/1. Tq/vk CmuxcnSE March 9, 1954 Filed Qct. 24, 1950 INVENTOR A/GEIPFOPD {BY I 2 ATTohNEY ROBE PT K //1/ Patented Mar. 9, 1954 "SYSTEM'FORMAINTAINING THE OIL LEVEL IN "THE CRAN'KCASE F INTERNAL-COM- BUSTI'ON ENGINES RobertK; Hungerford, West Hartford, .Conn.

Applicationfictober 24; 1950, Serial No. 191,752

13. Claims. 1

This invention is a system tori-maintaining properoil. level in the crank .case of an internal combustion engine and, while adapted forgeneral application, is particularly useful in connection with the engines of automobiles, trucks, buses and trailer tractors.

In practice, :ownersof; large fleets of trucks, busesand other commercialvehicles require a constant check onthe crankcase oil of such vehicles. Before these vehicles go. out .on a run, one of a corps'of men will .checko-ver the oil in each engine. This isdone by removing the usual measuring rod, wiping-it clean, reinserting it in the crankcase, and then withdrawing it again, in order to .get a proper reading of the oil conditions. Necessary oil is then introduced the operation of an electricmotor for drivingthe pump, the arrangement being suchthat. the-lewering of the oil -level in the crank. ease will-close the mastenswitch of the'circuit ofxtherpump motor. The motor circuit is, however, provided with a supplemental" switch adapted to:- re1nain and a re-readingis usually taken to be sure that I the oil level is'correct for that particular. engine. These operations are not too-burdensome-when a few trucks or buses are involved, but when a large fleet of trucks must be checked inthis manner, morning and night, the time required for this operation will run-into manyman hours. There has long been an .urgent need forsome satisfactory mea-ns to eliminate the time and labor thus expended.

Aside from thecommercial. aspect -of.this invention, the system thereof isapplicable to pleasure cars, automobilesand other vehicles where a person may forget to,check.the oil level, with resulting serious-damage to theengineand such damage. mayalso occur with. trucksand buses on long trips on thehighway.

.The primary. object of .the invention .is. .to provide for the automatic-feed of oil.. to .a crank case when the.oil level; in. suchcase' fallsbelow normal. accomplish this. result, but the structures. suggested. 'for the purposevhave not .met with general .favor. for. various reasons. ..Most.of..the.pro posed .prior. systems feedoil by gravity from an elevated supply .tank to .a .feed chamber. outside ofithe crank case and attempt tomaintain the levehin the crankcase bypslightlexcess in. the hydrostatic head vin .such external chamber. These-systemshave not .worked out satisfactorily. Furthermoremost of theseprior systems are. supposed-to feed oil to the crank case while the .engine is in operation. Sucha feed does .not satisfactorily work out. in practice.

The "present-invention overcomes these and other disadvantagesof the prior art in a simple and-eflicient manner. .Inits preferred. practical form the system..ofthis invention comprises an oil...s'torage tank. in .which.ansjappreciable body o f oilis adapted to be normally contained. This oil;is.adapted to 'be fed tQ-the crank-case bye open while the engine is in' operations-so that oil cannot be fed while the engineiis running. When the motor is at restrand this supplemental switch is closed, the motor circuit will be closed if the master switch-has-beenclosedubecauseof a low .oillevel condition-.inthecrankcaseand consequently oil will. be pump fed-to ..the..crank case until the-normal. level .-has..been re=established. The -fioat -will .then open--.the master switch and the flow ofoil toethe engine .willbe discontinued. With this arrangement. accurate metering of oil feed maybe obtained. Moreover the system may be so constituted thatthe. oil is automatically checked eachtime-theuengine is stopped, so. that. there. will be. .nmdanger. of run-.

adverted to, will be apparent from the herein- Attempts have heretofore been made to after d-etaileddescription and appended claims, when read in conjunction withthe accompanying. drawings. I

.The. accompanyingdrawing's illustratedififeren't practical embodimentsof the invention, but the constructions therein. shown .are to be .understood as illustrative. only, and not as. defining the limits of. theinyention. v

Figure 1 is a. diagrammatic view showing a system embodying the present invention without electrical connections. 7

Figure 2 is a vertical section through the wall of the crank case showing 'thefloat"anda'ssdciated master switch.

Figure 3 shows 'a fitting"interposed between the pump and the crank case'to-elir'nin'ate siphoning of oilfrorn thesup'ply" tankIihlmi ithE bESe when the pump isnotrunning.

Figure 4 is a wiring diagram showingthe adaptability of the system 1301311. engine-: haaxing a three position ignition switch.

Figure '5 shows: a diagram similar -vto.-. Eigure 4, but including a two. position..ignitionswitch.

. Figures. 6 and 7. corresponchtm-Eigures Land 5, but they illustrate a modification of the wiring to incorporate a relay switch in the pump motor circuit and in the pilot light circuit.

Referring to the drawings, l designates the crank case of an engine, with its normal oil level indicated 'at L. 'Within the crank case is located a float 2 connected to a lever 3 (Fig. 2). This lever is fulcrumed at 4 on a casting 5 secured to the interior of the crank case by stud bolts 6. These stud bolts 6 pass through the base of a housing 1, positioned externally of the crank case, and thread into the casting 5 to mount both the casting and the housing on the crank case with the housing exterior of the latter. A gasket 8 is interposed between the housing "I and the wall of the crank case. Within the housing 1 is positioned a master switch 9 provided with an operating button It]. A cover ll normally closes the open side of the housing and protects the switch from accumulations of dirt, oil and other foreign matter.

A plunger l2 extends through the base of the casting 5 and through perforations in the crank case and housing I, so that one of its ends is adapted for cooperation with a float lever 3 while its other end is positioned to act on a switch button l0. One end of a flexible bellows 13 has a fluid tight connection I4 with the plunger, while the other end of the bellows has a fluid tight connection l5 with a plate is interposed between the casting 5 in the crank case wall and tightly clamped therebetween.

The parts are so adjusted that, when the level of the oil is normal as indicated at L in Figure 2, the plunger will be withdrawn from the switch button ll! of the switch 9 of the master switch. To assure such withdrawal, the bellows 13 may be made slightly resilient to retract the plunger and hold it against the float lever 3. With this arrangement the master switch will be open when the oil level is at normal, but will be closed when the float falls below normal, due to recession of the oil level.

An appropriate supply of oil is adapted to be contained in a tank ll (Fig. l) to be fed through pipe l8 by a pump l9 which conveys the oil through a flexible hose to the crank case. In some installations it may be convenient to place the oil tank at a hi her level than the crank case. In such cases, there may be a tendency for oil to be fed to the en ine through the pump by a siphon action after the pump is shut oil. In such cases, it is desirable to include in the system an automatically operable air admitting check valve. This structure comprises a fitting. such as shown in Figure 3. This fitting. desi nated 2|, includes an air vent 22 to the atmos here, having therein a perforated seat 23 beneath whi h is a flan valve or disk 24. This disk 24 normally ravitates to a su port on pins 25 so as to vent the flexible hose 20 to the atmosphere.

However, as soon as the pump begins to pump oil a through the flexible hose 20, the pressure of this oil will elevate the disk 24 and close the vent. The vent will remain closed so long as oil is pumped through the flexible hose 20 but, as soon as the pumping stops, the disk 24 will fall away from the perforated'seat 23 and vent the flexible hose so'that the oil cannot siphon from the tank I! to the crank case. In other words, the oil is fed positively or it is not fed.

' The operations of the pump i 9 to feed oil to the crank case are primarily controlled by the master switch 9. Different wiring systems for accomplishing this result are shown in Figures 4 to 7, inclusive. The showing of Figure 4 is appropriate to an engine which has a three position ignition switch, such as indicated at 26. Here the power supply leading from the vehicle battery or generator is indicated at 21, while the wire 28 leads to the'distributor of the ignition circuit of the engine. When the movable contact 29 of the three position ignition switch is in the neutral position, shown in full lines in Figure i, the ignition is off, the engine is at rest and the whole electrical system is de-energized.

To operate the engine, the movable element 23 of the switch is engaged with the contact 39 to energize the ignition circuit in the conventional way. However, if the switch is moved from engagement with the contact 50 to stop the engine, and shifted to the left into engagement with the contact 3!, it will connect the power supply lead 21 with the movable switch element 9a of the master switch 9. If the oil level in the crank case is normal, the master switch element 9a will be in engagement With the contact 33 and will complete a circuit through a lead 34 to a green pilot lamp35 to ground. This lamp may be mounted on the instrument panel of the vehicle. As a result, the lamp will be illuminated and the operator will know that oil in the crank case is at normal level. The pilot lamp 35 thus acts as a visual indicator.

If, however, the oil level in the crank case is below normal, the float will have operated the plunger 12 of Figure 2 to move the master switch contact 911 into engagement with the contact 36 in Figure 4 and thus feed electrical energy through the wire 31 to a red pilot lamp 758 also positioned on the instrument board and grounded with respect thereto, thereby giving a visual indication that the oil level is low.

At the same time, current will be fed through a wire 39 to the oil pump I 9 with the result that the pump will be energized and will function to pump oil from the tank I! into the crank case. This feed of oil to the crank case will continue until the float disengages the movable contact 911 from the contact 36. The pump will then stop, the lamp 38 will be extinguished and the contact M will reengage with the contact 33, so that the lamp 35 will glow. As soon as the op erator sees that this condition prevails, the op erator will move the contact 29 of the three position ignition switch into the neutral position shown in Figure 4, leaving the pump at rest, the ignition circuit dead and the vehicle at rest.

When the engine is again put into operation by completing the ignition circuit, as hereinbefore described, the vehicle will function in a normal manner until it is again stopped, whereupon the operator may test the system by moving the contact 29 into engagement with the contact 3| as hereinbefore described. In other words, the mere flick of the ignition switch. when the car is brought to rest, will give a visual indication to the operator of the condition of the oil in the system and if insuflicient oil is indicated, he may operate the ignition switch as stated to replenish the oil as described.

The system of Figure 5 is the same as the system of Figure 4, except that in Figure 5 the ignition switch does not have a third contact. It is a single throw switch such as is found on many present day cars and trucks. It is necessary in this particular type of system to incorporate an additional manually controlled supplemental switch 40 which may be an ordinary push buttonrswitch. This. switch sls .lncludedlim-a lead 32ml connecting .the :powen supply. ;lead.-2 l- -.to:-;-the movablewarmfla of ithesma-ster switch: 9. v-When the. supplemental switch-:40 manually. closed, either-:of-the lampsi 35.:or 38wwill. be illuminated and,.if the (oil level iszlow, lamp 38=wi1l-.-glow,v the pump motor will be energizedandvwill :pump-oil as.in-Figure-4.

-In-systems of -Figures 4 and 5,: thecur-rent for Operating -thepumppasses through-.the Tmaster switch. .In some casesyth-is-may notbe: desirable. Figures Sand-"7. show how themaster switch may be .utilized tOcCODtIOl-rfi relay; switch which,=,.in turn,--controls the feed oLcur-renttrom' theacurrent source to the oil. pump motor and .tothe respective -pi1ot tlamps. .In these htwc .tlatter systems, engagement, of contact -29 I with contact 3|, while .the' contact ..9a.. of .the;.master switch 9 ;is,.engaged-with the contact 36, will cause current-to. be fed. from the -power supply through a magnet or solenoid 4| vof the, relay. When this .magnet or solenoid-is energized, it will. drawthe movable :contact- 42 of the relay into engagement with a contactJii-otsuch relay andthus completealcircuit from the power upply through .the contact. 29. of the ignition switch and .wire. 32 ton wire 44 to contact, 43 .and from that contact through wire 45 to the pump which is.,grounded. .thusecausingwthe pump .to operate andfeedoilinto lthe crank-case. At the same time .the. pilot llamp. 38 isenergized through lead 31a. -.lAs soon as ,the oil level is restored to normal,..the. contactJa-will.Jeave contacts 36, deenerg'izethe. coil 4| and the contact 42, being biased to its ifull;line..position, willmove :into engagementwith .thecontact 46. to breakzthe-pump circuit .and energize the greenpilotlamp 35. At thesame time thepilotllamp 3B wil1be extinguished andlamp '35 energized throughlead 35a.

The operations of the system..of..Eigure '7 will be apparent from the description of Figure 6 when it .is. remembered. that the onlydifierence is the use inFigure '7. of asingle throw. ignition switch .aridan additional supplemental switch 40.

It w'illbe apparent from the ioregoingthatthe present invention provides for the .positivepressure feed, or on to the crank case. while. the. vehicle is at rest for it is orilyat that, time -thatan accurate metering of .the oil to a predetermined level can be obtained. When the vehicle is in motion, the sloshing about .of the oiljin the crank .case makes accurate metering impossible. However, when the vehicle isat rest and the surface of the .oilcomes "to aquiescent-levehan accurate feed may be obtained and this 'thepresent "invention provides.

In each of "the foregoing. diagrams, there is a switch (contacts 29 and3ll, Figs. 4 and.6 and single throw switch Figs. 5 and 7) to control the feedof current from the current source to the distributor of the ignition system and a supplemental switch .i-insseries zwith ...the .master switch to control the .oil feed. In Rigs. 4 and 6 this supplemental switchsis composed of the movable-contact 29 and the fixed-contact 31,.of. the conventional-:nthree position ignition switch. ."..In Figs. 5-.and'7 this supplemental; switch :is :indicated at 40 .as a switch structure in addition to the conventional single throw. iignition rswitch. The present iinvention may thuss'be readily :installed on-vehicles with either type ofsignition switch, without change of the conventional ignition system.

Through the use of thisinvention, recourse .to the conventional measuringqrod. is entirely-unnecessary. .?-A11nthat;risr nequirediisii'ithat'zian'sia tendant or operator fill the storageg tank i 'l .z-from time 112011511116. Asdnngsiassthere is :a supply of oil im-thistank, tlnesengine imaywbe zpperated safely from the standpoint-ref acrankwcase :lubrication. Alhthat .one has stoldougis :tollift the cover. vfrom the tank I! and pour in oil untilwthe tank:isPfull andrthen repiaice.ithemover. 'An: adequate supply of; oil 51s thereby: :made available ati all times and ii-the operatorwill ;from "time to time.- either prlessithe.supplementalswitch ort rnthe; ignition switch,:.to: the -l'ethzas. indicated-ii F iguresr-erand 6, there need; the; 1110i fear ;.of- .anvinadequate oil supply. In: iadditionoto itheractual: operation of the: system to.=feed..:the:o i1, thew Operator cam-see at. aeglancer the ieonditiorriofwthe :oil ;by.-Ethe:,:illuminationz'Of; the respeotivespilot :lamps. ith the: oil mressureieed I described, the i-uncertainties of; gravity feed or the dependencer upon-idifierential pressures,- asihas; sometimes beenrtr-ied; is rendered :unnecessarywasihemil feed 0f Lthis Lin- .ventionqisipositiverandiunfailing in:its:xop.eration. It will also be noted :thatiin the; systemof the present invention; 33116130131310 of. the ifzeed. of oil to --thecrank :case mambo-accomplished :--from: the instrument? panel without-acquiring. rthei drivjercto leavehis-seat. The lpil'ot- -.lampsZ-- 35.-.and: 38 were also on: the; instrument: lpanelnandioan; bei iseen bythe driverwheniininormal driving position.

,lE-xperience' with/the;isystemaof. this; invention has shown that itis. particularlycritical to relati-velysmall variations inr oil: ilevlel. other Words,- a'-recession in the. oil level; resulting from the:useoL-arelatively small. partror; a.pint of oil, will-bringl-about an indication: oi-lowered "oil level and the feedi orreplenishing operation is'iequally as .close.

, In the ioregoing .1 detailed": description, .i I" have set forth the. inventionriasnparticularlymadapted 1 forv luse -in-- connection with. :the' oil level in the crank-bases of internal combustion engines. 1 I am .aware,=.:however, thatkit may be adapted to other. .uses-swhere ;-1iquidile.vels aresinvolved'; for example,-.sin connectionwith-large- -air.:c'ompressors .or I anywhere-elsewhere liquid 5 levels: are to be lmaintainedr-anct it willherconvenient or: desirahleto iireplenishstheilevel from time. to time in: a :more or lesswautomatic, manner.

' I The foregoing detailed; description @setsi -;f orth the -.in-vlention. in its-gpreferred practical forms, but theiiinventionds toe-be:understoodas fully commensurate withsthe; appended; claims.

,Havingthus fully described the invention; what Ir-claim as. :new -.-.an'd-d'esire sto 'secure by Letters Patent: is:

.leAe systemeof ithe zcharacter described-..acomprising :an internal z-combustion engine. having a cranlc -case.-.\ands:an-ignition system including --a source .ofi-electric current and ignitionswitch, .in combination withsaafloat in. the crank 1 case responsive to. the. oil level therein; .a master switch operativelywconnected withtthe float to be closed byltheJatter. whengthe oil .level recedesJaelow-a pred'eterminedjlelevation,, a vsource of ':-oil supply,

, amotoroper'ated pump connected tosaid oil allyicontrolled by... a..supplemental.switch.

.12., A..1syst.em; as .1 claimed .;in.. cla'iml, ,wherein said; supplemental swlitchis the. .ignition-switch. .13.; JA. system..-.as. claimed in, claim 1, --wherein 7 said supplemental switch is shunted across the ignition switch.

4. A system as claimed in claim 1, wherein the master switch is located externally of the crank case and is operatively connected to the float through an impervious protective seal at the wall of the crank case.

5. A system as claimed in claim 1, wherein the piping connection between the oil supply and the crank case is provided with an automatically operable air admitting check valve to eliminate syphoning of oil from the oil supply to the crank case while the pump is not operating.

6. A system of the character described comprising: an internal combustion engine having a crank case, in combination with a source of oil supply, a pump connected by a conduit to both the source of oil supply and the crank cas to pump oil from the former to the latter, and an automatically operable air admitting check valve included in said conduit to eliminate syphoning of oil from said source to the crank case while the pump is not operating.

'7. A system of the character described comprising: an internal combustion engine having a crank case and an ignition system including a source of electric current and an ignition switch, in combination with a float in the crank case responsive to the oil level therein, a master switch operatively connected with the float to be closed by the latter when the oil level recedes below a predetermined elevation, at source of oil supply, a motor operated pump connected to said oil supply and piped to the crank case to pump oil from said source to the crank case when the motor is energized, and a motor circuit including the source of electric current, the master switch and the ignition switch and closed by the latter only when the ignition circuit is shut oil.

8. A system of the character described comprising: an internal combustion engine having a crank case and an ignition system including a source of electric current and an ignition switch, in combination with a float in the crank case responsive to the oil level therein, a master switch operatively connected with the float to be closed by the latter when the oil level recedes below a predetermined elevation, a source of oil supply, a motor operated pump. connected to said oil supply and piped to the crank case to pump oil from said source to the crank case when the motor is energized, a motor circuit including the source of electric current and also the motor and a relay switch, and a controlling circuit including the source of electric current and also the master switch and the ignition switch and energized to close the relay switch to energize the motor when the master switch is closed and the ignition switch is in condition to shut off the ignition and close said controlling circuit.

9. A system of the character described comprising: an internal combustion engine having a crank case and an ignition system including a source of electric current and an ignition switch, in combination with a float in the crank case responsive to the oil level therein, a master switch operatively connected with the float to be closed by the latter when the oil level recedes below a predetermined elevation, a source of oil supply, a motor operated pump connected to said oil supply and piped to the crank case to pump oil from said source to the crank case when the motor is energized, and a motor circuit including the source of electric current, the master switch and a manually operable supplemental switch.

10. A systemor the character described-comprising: an internal combustion engine having a crank case and an ignition system including a source of electric current and an ignition switch, in combination with a float in the crank case responsive to the oil level therein, a master switch operatively connected with the float to be closed by the latter when the oil level recedes below a predetermined elevation, 21. source of oil supply, a motor operated pump connected to said oil supply and piped to the crank case to pump oil from said source to the crank case when the motor is energized, a motor circuit including the source of electric current and also the motor and a relay switch, and a controlling circuit including the source of electric current and also the master switch, and a manually operable supplemental switch and energized to close the relay switch to energize the motor when both the master switch and the supplemental switch are closed.

11. A system as claimed in claim 1, including pilot circuit having indicators to respectively indicate the state of the oil level in the crank case when the supplemental switch is closed.

12. A system of the character described comprising: an internal combustion engine having a crank case, in combination with a source of oil supply, a pump connected by a conduit to both the source of oil supply and the crank case, a motor for driving said pump to deliver oil from said source of oil supply to the crank case, an automatically operable air admitting check valve included in said conduit to eliminate syphoning of oil from said source to the crank case while the pump is not operating, an electric circuit including said motor and a master switch, and a float positioned in the crank case for operating the master switch to cause operation of the pump when the oil level in the crank case recedes below a predetermined elevation.

13. A system of the character described comprising: an internal combustion engine having a crank case and an ignition switch, in combination with a source of oil supply, a pump connected by a conduit to both the source of oil supply and the crank case, a motor for driving said pump to deliver oil from said source of oil supply to the crank case, an automatically operable air admitting check valve included in said conduit to eliminate syphoning of oil from said source to the crank case while the pump is not operating, an electric circuit including said motor and a master switch and also the ignition switch of the engine, and a float positioned in the crank case for operating the master switch to cause operation of the pump when the oil level in the crank case recedes below a predetermined elevation.

ROBERT K. HUNGERFO RD.

References Cited in the flle of this patent UNITED STATES PATENTS Number Name Date 1,358,741 Hollis Nov. 16, 1920 1,484,641 Goodwin Feb. 26, 1924 1,725,208 Potter Aug. 20, 1929 1,883,202 White Oct. 18, 1932 1,945,317 Kalin Jan. 30, 1934 2,316,000 James Apr. 6, 19513 FOREIGN PATENTS Number Country 0 Date I 222,914 Germany June 9, 1910 

